books.google.com - This is an updated version of the best selling first edition, Ecological Census Techniques, with updating, some new chapters and authors. Almost all ecological and conservation work involves carrying out a census or survey. This practically focussed book describes how to plan a census, the practical...http://books.google.com/books/about/Ecological_Census_Techniques.html?id=rTJdia64ACMC&q=aquatic&utm_source=gb-gplus-shareEcological Census Techniques